Light fixture assembly



, p 1966 M. H. KRUGER LIGHT FIXTURE ASSEMBLY 2 Sheets-Sheet 1 Filed Nov. 29, 1965 Sept. 6, 1966 M. H. KRUGER 3,271,570

LIGHT FIXTURE ASSEMBLY Filed Nov. 29, 1963 2 Sheets-Sheet 2 United States Patent 3,271,570 LIGHT FIXTURE ASSEMBLY Michael Henry Kruger, Chestnut Hill, Mass., assignor t0 Smithcraft Corporation, Chelsea, Mass., a corporation of Massachusetts Filed Nov. 29, 1963, Ser. No. 326,987 8 tjlaims. (Cl. 240-5111) This invention relates to fixtures for fluorescent lamps, and in particular to a novel means for suspending the lamp holders and lamps in a main reflector housing.

Through the years a great deal of attention has been given to the problem of how best to attach the individual fluorescent lighting units, each comprising two larnp holders and an elongated lamp, to the housing, to give flexibility as well as ease of installation and servicing. Normally, prior to the present invention, the holders have been screwed or bolted to the main housing, or secured against it by other parts that are screwed or bolted in place. Not only is the process of installation or removal thus complicated, but it becomes necessary to structurally alter the fixture in order to change the number of individual lighting units therein suspended. Often such a change is impossible, due to the complete incorporation of the sockets in the structure of the fixture.

It is thus an object of the invention to provide novel means for suspending lamp holders in a fluorescent fixture, so that said holders can be installed or removed without inserting or removing any screws, bolts or other similar fastening devices, and without performing any but the simplest of mechanical operations upon said fixture.

It is a further object of the invention to provide a fluorescent fixture, in which the number of individual lighting units therein suspended can be quickly changed without the need of any structural alterations in said fixture, the number of individual lighting units being limited only by the overall size of the fixture.

Further objects and advantages of the invention will become apparent upon its detailed description.

The objects of the invention are accomplished with a minimum of parts by using a main reflector housing and end caps of novel design, said housing and end caps cooperating to form secondary lampholder locating and supporting channels extending along opposite ends of the housing transverse to the direction of extension of the elongated fluorescent lamps. The channels are shaped to receive the block portion of a standard tombstone holder, the hanger portion of said holder extending vertically through a slot in the floor of the channel.

The holders are spaced and locked in the channel by novel primary locating and supporting elongated spacer strips that are preferably flexible about one transverse axis to allow easy installation but relatively stiff about all other axes to firmly position and lock the lamp holders. The holders are first inserted into openings in the spacer strip, and the holder-bearing spacer is then threaded into the channel. Holders are thus easily installed or removed by the simple process of sliding the spacer in and out of the channel. Furthermore, the number of individual lighting units in the fixture is dependent only upon the overall size of the fixture and the number of holder-receiving slots in the spacers, the capacity of the fixture thus easily changed by simply changing the spacer, a variety of spacers being provided.

The invention will be best understood by referring to the preferred embodiment shown in the accompanying drawings, in which:

FIG. 1 is an exploded view showing the main housing, an end cap, a spacer and a socket;

FIG. 2 is a vertical transverse section of an assembled fixture;

FIG. 3 shows a spacer capable of accommodating two lamp holders, for use in a four-light fixture;

FIG. 4 shows a spacer capable of accommodating three lamp holders, for use in a six-light fixture;

FIG. 5 shows a spacer capable of accommodating one lamp holder on one side, and, in conjunction with a similar spacer (not shown), three holders on the other side, for use in either a two-light or a three-light fixture;

FIG. 6 is a horizontal section of an assembled fixture taken along the line 6-6 in FIG. 2;

FIG. 7 is a vertical section of an assembled fixture, the section taken parallel to the direction of extension of the fluorescent lamps along the line 77 in FIG. 6;

FIG. 8 is a perspective view of a socket;

FIG. 9 is a vertical section similar to FIG. 2, showing the manner in which the lamp holders and spacers are threaded into the channels.

Referring to the drawings, the fixture includes a main reflector housing 15, two end caps 35 (only one shown), spacer strips 52, lamp holders 44 and a lower shield 64.

The main reflector housing 15 has a central ballast housing portion 16, containing the ballast and through wiring, said central portion 16 comprising a horizontal top 17, and downwardly, laterally sloping sides 18. Flat top reflectors 21 are arranged symmetrically about said central portion 16, and extend laterally and upwardly from the lower edges of sides 18 of central portion 16. As will be more fully understood below, the upward slope of top reflectors 21 facilitates the threading of the holder-bearing spacer strips into their respective channels. In addition, the sloping results in increased distance between the lamps 65 and the translucent lower shield 64, with the outer lamps being farther from the shield than the inner lamps, as best shown in FIG. 2. The increased lamp to shield distance, and especially the variation of that distance from lamp to lamp, provides a wider and varying solid angle of light impinging upon the shield directly from the lamps and hence improves the distribution and uniformity of the light as it flows through the shield. The upward slope of top reflectors 21 is preferably such that the lateral edges 22 of said top reflectors lie in the plane of top 17 of central ballast housing portion 16, thus facilitating rectangular packaging of the fixture.

Extending generally downward from lateral edges 22 of top reflectors 21 are side reflectors 23. In the present embodiment these side reflectors comprise downward and outward sloping portions 25, vertical portions 26, downward and inward sloping portions 27 and lower vertical portions 28.

The inner surfaces of the top and side reflectors are coated so as to provide the desired reflectance characteristics.

Extending along each transverse edge 24 of top reflectors 21 from a side 18 of central ballast housing portion 16 to a lateral edge 22 of a top reflector 21, is a right angle channel forming member 30, there being a total of four such members, two of which are shown. Each member 30 consists of a first wall 31, extending vertically downward from edge 24, and a second wall 32, extending perpendicularly away from the lower edge of said first wall, in the direction away from top reflector 21. First wall 31 is of a depth slightly greater than the vertical thickness of block portion 4 5 of lamp holder 44, said block portion thus being able to rest upon the second wall 32, with a spacer strip 52 lying between said block portion and second wall 32, without the block portion protruding above the surface of top reflector 21, as best shown in FIG. 7.

End caps, one of which is shown at 35, fit against the ends of main housing 15, as best shown in FIGS. 1 and 7. Considering the detailed construction of end cap 35,

ice

FIG. 1 shows the flat end plate 36, flat top plates 37, and side flanges 38 and 39. End plate 36 has upper flap extension 40, and lower extensions 41 and 42, extension 40 being sloped inwardly and extension 41 being vertical and terminating in shield-supporting flange 43, as shown in FIG. 7. End cap 35 is thus adapted to fit snugly over and be screwed to the end of main housing 15, with side flanges 38 and 39 overlapping the ends of side reflector portions 25 and 28, respectively. Upper flap extension 40 covers the open end of central ballast housing portion 16. Lower flange 43 fits under the main housing and helps to support the lower shielding. As shown in FIG. 7, top plate 37 overlaps top reflector 21 to form the upper wall of a transverse channel 50. End plate 36 is vertically positioned parallel to first wall 31 of right angle channel-forming member 30, to form the rear wall of said channel 50. Second wall 32 of the channel-forming member extends partially across the bottom of said channel 50, being spaced from end plate 36 to form a transverse slot 51 wide enough to admit the hanger portion 46 of a holder 44. Similar channels 50 run along all four edges 24. It will thus be observed that, by means of the novel design of the main housing and the end caps, the fixture has been provided with slotted transverse channels along its opposite ends, said channels formed as integral parts of the fixture. The number of parts is thus kept at a minimum, and assembly is kept extremely simple. In the present embodiment of the invention, only 12 screws are used to assemble the entire fixture, six screws attaching each end cap to the main housing, with typical screw positions indicated at 6163.

The sockets 44 are preferably of the well-known tombstone type, having a block portion 45 and a vertically extending hanger portion 46, as shown in FIG. 8. The hanger 46 is shaped to hold the end of a fluorescent lamp in a lamp-receiving socket 47. Running along the top of the hanger, just below the block, are grooves 48, said grooves aiding the secure positioning of the lamp holders in the transverse channels 50, as is further explained below.

Spacer strips 52 are employed to position and lock the lamp holders in the transverse channels. Each spacer 52 consists of an elongated rectangular strip of material, such as melamine, thin stainless steel, or a phenolic plastic, cut in the form of a template, with transverse edges 53 longitudinal edges 54, holder receiving openings 55 cut into one transverse edge 53, and tongues 56 protruding from one longitudinal edge 54, preferably providing continuations of transverse edges 53. Said socket-receiving openings 55 are adapted to snugly accommodate holders 44, with the sides of said openings fitting into the grooves 48 in said holders. The width of said spacer strip between its transverse edges 53 is such that it will fit snugly between first wall 31 of channel forming member 30 and end plate 36 when inserted into channel 50. The length of said spacer between its longitudinal edges 54 is such that it will extend, when inserted in channel 50, from its point of contact with portion 25 of side reflector 23 to a point beneath the ballast midway between the two top reflectors. The space strip is flexible about its short transverse axis but otherwise resists deformation, in order to best perform its positioning and locking function.

The process of installing lamp holders 44 in the fixture will now be described. First, the holders are inserted into the receiving openings 55 in the spacer strip with the lamp-receiving sockets 47 facing the transverse edge 53 of the spacer opposite that edge in which the openings 55 are cut. All wires are connected at this time. The holder-bearing spacer is then threaded into the channel 50 as shown in FIG. 9, with the sockets 47 facing inwardly. The upward slope of the top reflectors 21 facilitates the threading. The spacer is inserted so that the tongues 56 lie beneath the ballast. When a second spacer is similarly inserted in the opposing channel, the tongues 56 of the ppposing spacers will interlock, as

shown in FIG. 6, to prevent the spacers from sliding out of their respective channels. Similarly, holder-bearing spacers are inserted in the other channels, and the lamps are then connected between opposing sockets. Besides spacing apart the holders, the spacers also aid in the support of the sockets by extending the floors of channels 50 over the transverse slots 51. Transverse channel 50 is preferably sized to hold the block 45 of holder 44 as snugly as possible. The spacer strips thus serve as the primary locaters and supporters of the lampholders, while the channels serve as secondary locaters and supporters of the lampholders in addition to locating and supporting the spacer strips in slidably removable fashion.

In the above manner, any desired number of individual lighting units may be installed in a given fixture depending upon its overall size, by simply choosing an appropriate set of spacer strips. In a four-lamp set-up, each spacer will have two openings. In a three-lamp set-up, if the lamps are to be evenly spaced, each spacer will have one full opening and one-half opening, a set of two interlocking strips thus giving three openings. Advantageously, each strip can be adapted for use in two set-ups, by having a different set of openings along each transverse edge, as shown in FIG. 5. It will be observed that the installation or removal of individual lighting units is extremely simple, requiring no screws or other fastening devices, and no mechanical operations on the fixture itself. Wiring runs from the central ballast housing portion, through the transverse channels to the individual sockets.

Inverted T elements 66 may be provided externally, as shown in FIG. 2, to support lower shield 65, said shield constructed of translucent material.

Modifications of the particular structure described that are within the spirit and scope of the invention will readily occur to those skilled in the art, the invention being limited only by the appended claims.

What is claimed is:

1. A lighting fixture assembly adapted to suspend elongated fluorescent lamps in lamp holders having socketbearing portions, comprising a main fixture with secondary lamp-holder locating and supporting channels extending along the opposite ends of said housing transverse to the direction of extension of said lamps, each said channel having a pair of transversely extending opposing walls, and primary lamp holder locating and supporting elongated spacer strips sized to slide transversely into said channels, said spacer strips being removably located and supported by said channels between said walls and having openings for receiving and in turn 10- cating and supporting said lamp holders.

2. The assembly of claim 1 wherein said channels are arranged in symmetrically opposed pairs, sloping upwardly and laterally away from the central longitudinal axis of said fixture and said spacer strips provide tongues protruding transversely toward the center of said fixture when said strips are installed in said channels, said strips opposing each other in pairs and the tongues of opposing spacers adapted to interlock, thereby preventing said strips from sliding out of their respective channels.

3. The assembly of claim 1 wherein said channels have partially open floors providing slots running along their length, said slots being of a width slightly greater than the thickness of the socket bearing portions of said lampholder, said spacer strips are of a width slightly less than the width of said channels, said lamp-holder-receiving openings are located to coincide with one of said slots when the strip is inserted into the corresponding channel, said openings and lampholders are sized so that each said opening is capable of accommodating at least one horizontal section of a lampholder but incapable of accommodating at least one horizontal section located above said first mentioned horizontal section, said openings are of a width and depth slightly larger than the width and thickness of said first horizontal section, and said spacer strips are substantially rigid against deformation in their own plane.

4. An elongated strip adapted to be used for the positioning in a main fixture of fluorescent lamp holders having horizontal block portions and vertically extending socket-receiving portions, said fixture having secondary lampholder locating and supporting channels each having a pair of opposing Walls, said strip sized to slide into one of said channels, said strip when in said channel being removably located and supported by said channel between said walls, said strip having lamp holder-receiving openings along one long edge, said openings having a width and depth slightly larger than the width and thickness of said socket-receiving portions, said strip being rigid to deformation in its own plane.

5. Positioning strips as described in claim 4, each strip being resilient and having at least one tongue at one of its ends, said fixture having two inclined reflector surfaces, said strips insertable in opposing pairs into said channels from the junction of said reflector surfaces with said tongues of opposing strips opposing each other and said opposing strips being interlocked at said tongues.

6. A pair of positioning strips as described in claim 5 wherein said strips are adapted to position a lamp holder at their point of interlock, each strip having a lamp holderreceiving opening of half normal width at its interlocking end, said two half width openings combining to receive said lamp holder.

7. A lighting fixture assembly adapted to suspend elongated fluorescent lamps in lampholders having socketbearing portions, comprising a main fixture housing having top, side and end walls, and a lampholder assembly adapted to be inserted into said main fixture housing without affecting the structural relationship of said end walls with respect to the remainder of said main fixture housing, said main fixture having secondary lamp-holder locating and supporting channels extending along the opposite ends of said housing transverse to the direction of extension of said lamps, said transverse channels having entry openings located inwardly of said side walls, said lampholder assembly comprising primary lampholder locating and supporting elongated spacer strips sized to slide lengthwise through said entry openings into said channels, said spacer strips being supported transversely to the direction of extension of said lamps by said channles and having openings for receiving and in turn locating said lampholders in said housing.

8. The assembly of claim 7 wherein said channels are arranged in symmetrically opposed pairs, sloping upwardly and laterally away from the central longitudinal axis of said fixture.

References Cited by the Examiner UNITED STATES PATENTS 2,362,091 11/ 1944 Parlato 24051.11 2,531,533 11/1950 Shaw 240-51.11 X 2,914,657 11/1959 Akeley et al 240-51.11 X 2,982,850 5/1961 Lister et al 2405l.11

NORTON ANSHER, Primary Examiner.

CHARLES R. RHODES, Assistant Examiner. 

1. A LIGHTING FIXTURE ASSEMBLY ADAPTED T SUSPEND ELONGATED FLUORESCENT LAMPS IN LAMP HOLDERS HAVING SOCKETBEARING PORTIONS, COMPRISING A MAIN FIXTURE WITH SECONDARY LAMP-HOLDER LOCATING AND SUPPORTING CHANNELS EXTENDING ALONG THE OPPOSITE ENDS OF SAID HOUSING TRANSVERSE TO THE DIRECTION OF EXTENSION OF SAID LAMPS, EACH SAID CHANNEL HAVING A PAIR OF TRANSVERSELY EXTENDING OPPOSING WALLS, AND PRIMARY LAMP HOLDER LOCATING AND SUPPORTING ELONGATED SPACER STRIPS SIZED TO SLIDE TRANSVERSELY INTO SAID CHANNELS, SAID SPACER STRIPS BEING REMOVABLY LOCATED AND SUPPORTED BY SAID CHANNELS BETWEEN SAID WALLS AND HAVING OPENINGS FOR RECEIVING AND IN TURN LOCATING AND SUPPORTING SAID LAMP HOLDERS. 